I think that, rather than the current Caster situation of 'BLM for big brain, SMN for easystreet, RDM for prog' or whatever, each job should have its own individual sliding scale of complexity. Take SCH. If someone wants to spam Broil as their damage rotation, then they should be able to do that for any content without an Enrage (and they can). But if someone wants to spin a lot more plates, juggling three different DOT timers, they also should have the option to. We keep hearing about how 'people want to play X job for the aesthetic, but don't want to put the effort in to learn it', but the opposite must be true as well. If I want to play a complex healer, but also I like the WHM aesthetic, then I should be able to play WHM with a degree of complexity. It shouldn't be that I have to accept I'm playing 'the simple healer, for players who want a more casual experience'.
Said 'complexity' can be made 'optional', or at least, 'much less punishing' with simple potency value tuning. I like to use SCH as an example:
Broil 5: 300p
Biolysis: 35p per tick for 30s (total 350p)
Miasmalysis: 20p, then 30p per tick for 24s (340p)
Shadowflare: 120p, then 40p per tick for 15s (320p)
By making the potency 'gained' from engaging with the extra complexity be a smaller amount, it makes it feel less 'required'. In this example, by using Broil in place of the DOT refreshes, the player would lose a total of 560p over two minutes. By comparison, the 6 Energy drains you'd get over that duration would be 600p. Casual players would not care about 'Oh I cast a Broil there instead of refreshing my Biolysis on time, I just lost about 5 potency' (maths means it's an average of 5p lost, not 35p). But optimization players WOULD care about the difference between Broil spam and 'optimal gameplay' of refreshing all the DOTs on time, because it'd result in more damage, no matter how slight the increase is. If Energy Drain is enough of a reason to try and optimize around, even at 100p, then something like this would be too.
With the current DOT situation on healers, of 30s duration and their being over 200% of the damage of a filler spell, they've got the worst of both worlds: They've got a huge impact on our damage output (meaning dropping them is more punishing), and at the same time, their longer duration can make it harder for some players (for example, me) to remember that it needs to be refreshed (meaning it's more likely to get dropped for a few ticks). I never had this issue back when we had Aero at 18s or Aero2 at 12s back in HW
Did you know that at one point, BRD's Venomous Bite was only 9s duration?